Informative. Thought provoking. Inspiring. The 2nd World Forum on Urban Forests had all three in abundance. From Monday, October 16 through Thursday, October 19, 2023, one thousand attendees from sixty countries the world over gathered to hear individual speakers and panel discussions.

The streets of Washington, DC brimmed with greenery, and field trips would take participants to some fascinating locales all around the city.

First, though, conversation and education. Energy crackled in the air as people talked with colleagues and forged new bonds.

There was far too much information to offer in a single summary. Here are some of the highlights, along with comments from participants about what they liked best about the conference.

Simone Borelli, Urban Forestry Officer with the United Nations Food and Agriculture Organization, opened the conference, speaking to a packed crowd about the important role of participats in promoting “a more sustainable and harmonious urban environment. It’s about green cities for all.” The proceedings of the next three days, he explained, would be in three parts. “Number one, how urban forestry contributes to public health. Number two, how urban forests can be managed so they’re accessible to all people. Number three, strategies to strengthen the resilience of cities in terms of their green infrastructure.”

Dan Lambe, Chief Executive Officer of the Arbor Day Foundation, followed with a wake-up call in which he told the group, “These are the folks that are doing what you’re doing in every corner of the globe. Trees bring people together to do great things. We all have a common spirit of wanting to do the right things in our communities regarding trees. Our work has never been more important than it is today. Now is our time.”


2nd World Forum on Urban Forests Welcome
Washington, DC Magnolia
Simone Borelli
Joy Mutai, Ayanda Roji

Joy Mutai, visiting from Kenya, said, “What I like is the passion of everyone for urban forestry, and the program is well thought out, with concrete discussions on health, equity and resilience. And there is a diverse group of stakeholders.” Ayanda Roji, attending from South Africa, added that she appreciated “people from all the continents of the world, and the focus on social infrastructure and community engagement — taking care of trees and the context and focus on the meaning of trees, their relevance. And integration is emphasized.”

Chief Mark Tayac shared a land acknowledgment at the meeting’s start. Beforehand, Tayac, a member of the Piscataway Indian Nation, explained that “for forty-plus years I’ve worked to bring recognition to the plight of the Indigenous people of this land. I’ve traveled around the world speaking about tradition and nature.”

Tayac’s grandfather, Chief Turkey Tayac, was the 27th generation of hereditary chiefs, and Tayac is the 29th generation. His grandfather, he told the crowd, died in 1978 and was buried underneath a red cedar. “We’re connected by this ancient tree of life – the oxygen the tree produces, our people inhale it.”

The organizers of the conference introduced themselves with personal anecdotes about what made trees meaningful for them. Nicholas Verloop, President of the International Society of Arboriculture, noted that this is the 100th birthday of the organization. Maria Chiara Pastore, Associate Professor at the Politecnico di Milano, described herself as “a bit emotioned to be here today.” She spoke of “the importance of alliances and collaboration to bring people together from different disciplines to have happier, healthier and more resilient cities.”

Chief Mark Tayac

Fabio Salbitano, Associate Professor at the University of Sassari, Italy, talked about spending his childhood “in the mountains in remote areas,” and how those formative years fueled his love for forests. Beattra Wilson, Associate Director for Urban and Community Forestry with the United States Forest Service, recalled how the pear trees of her youth provided sustenance. She spoke of the “absolute importance of urban forestry,” saying that “it would be negligent to leave the underserved behind” and extolling “the diversity of faces that affirm why we are here and need each other.” Director of Smithsonian Gardens Joy Columbus reminded people that “our trees have the potential to tell American history.”

Ali Zaidi, Assistant to President Biden and National Climate Advisor to the White House, delivered an inspirational message, asserting that “the investment we make in urban forests helps us get out ahead of a sense of powerlessness…to boost resilience and to do the hard work of repair in places that were historically redlined. It’s a fight against historical injustice.” He added, “You should have a sense of how incredibly powerful you are.” President Biden has just launched the American Climate Corps, and “building out our forests will be key. We have to grow our ability to get tools into the hands of people who need them. We’re going to work like heck to get the dollars flowing where they need to.”

World Forum Conference Planners
Jasmine Putney, Leah Keller

Jasmine Putney said, “It’s just wonderful to see everybody come together to celebrate trees.” Leah Keller added, “It’s really interesting to see everyone’s perspectives and how they can work together and make each other strong.”


Aruni Bhatnagar of the University of Louisville’s Department of Medicine summarized the work being done to understand the link between health and the environment. The leading cause of death worldwide is heart disease, and sixty to eighty percent of chronic heart disease, he said, is preventable. He shared the scientific data pointing to a higher cancer survival rate for those living in green areas. People who spend time in the outdoors have less asthma, stronger social bonds, better mental health, better cognition and better immunity to disease, “because plant antigens educate the immune system.”

Patients in hospital rooms with a view require less medication and are released on average a day earlier. The Green Heart Project in Louisville planted thirty thousand large evergreens and deciduous trees in low-income, racially mixed neighborhoods and correlated the “greenness of different areas” with health, measuring heart rate and stress levels, to understand peoples’ physical responses. Conclusion: “You need to look at the whole environment, not just trees.”

Aruni Bhatnagar
Andrew Decker

Andrew Decker, Senior Forester with The Greening of Detroit, observed, “The majority of our work is tree planting and green infrastructure. It’s interesting to see how the cities and nonprofits are accomplishing the same goals and overcoming problems. Comparing how we can do something different.”


Ming Kuo, University of Illinois Associate Professor of Natural Resources and Environmental Sciences, summarized her thirty years of research into “maximizing green person-minutes.” She posed the question, “What kinds of nature experiences promote health the most? Meadows, forests, lakes, wild or manicured, nature as focus or backdrop?” She said, “Trees seem to be special, especially large trees. What’s less helpful? Grass. Turf.” And “big doses of nature have big impacts. People who have a lot of natural killer cells have less cancers. And just three days of wandering around in a natural forest area increases your natural killer cells by fifty percent. Plus, it’s nice. It’s a form of medicine that we actually enjoy. Even the smell of roses can make a difference, to flip us from fight or flight to happy.” The biggest bang for the buck comes with total exposure time – “the nature that’s in your face makes a difference.”

Her conclusion: “Providing nature for health offers a high return on investment. Greening more than pays for itself. The future is more urban and more dense, and so greening for health will only become more important.”

Ming Kuo

Matthew Lopez-Jensen, an environmental artist and educator at the New School and Fordham, presented about “Creative Community Engagement Strategies for Green Infrastructure Projects.” In his work he tries to “anchor action in the community.” Lopez-Jensen partners with local environmental activist groups: “I try to cure plant blindness a little bit.” One of his current projects pairs the concept of storm water management with embroidery. In conjunction with a plan to daylight Tibbetts Brook, he visualized marshland on green rooftops along the water, then developed a fabric representation completed with volunteer stitchers and exhibited at New York City’s Van Cortlandt Manor in 2022.

He is also Erie Canal Artist-in-Residence, for which he produced a project called “The Work and the Water.” Forty employees tell how they interact with the Canal – “a year’s worth of adventures and conversations.” The artist says that he “likes to teach people to say, ‘Remember when we’ rather than ‘Remember when they’”—in other words, to encourage the idea of environmental stewardship. Something that excited the audience perhaps most of all was Lopez-Jensen’s “New York street tree tarot deck,” featuring seventy-eight cards that picture city scenes. “For five years,” he said, “I’ve been photographing street trees as an extension of ourselves.”

Matthew Lopez, Cindy Braun
NYC Street Tree Tarot Card

Bram Gunther, Vice President of PlanIt Wild and former Chief of Forestry for New York City Parks and Recreation, presented on the subject of “Swale,” a 130-by-140-foot floating food forest that docks in harbors around NYC. Part art installation, part community engagement project, Swale was launched in July 2016 after a year of planning and building in collaboration with numerous community groups.

The artist Mary Mattingly, who created Swale, had done public art in the past, and in this case the project was self-sufficient, with plumbing and food crops on board, welcoming people to harvest food. Gunther reminded the audience that there are 30,000 acres of park in New York City, including 11,000 acres of green parkland. During summer 2016, Swale docked in the Bronx at Concrete Plant Park, Brooklyn Bridge Park and Governors Island. The Bronx is one of the largest “food deserts” in the United States, Gunther said – “but it also has Hunts Point market, which sells much gourmet food that does not stay there.” The launch of Swale acted as a literal and figurative platform to discuss the necessity of universal food accessibility.

“The community really took to Swale because of issues they’re dealing with on a daily basis.” At first, children came on board to forage, but “after they did their parents joined them.” A class at Pratt has designed the next generation of Swale as a functional recreational place, suggesting that “dream projects might lead to dream actions.”

Bram Gunther, Doug Still

According to Doug Still, “My favorite talk was an arborist from Ukraine who spoke about doing a tree eco study during the current war. It was moving and we all gave it a standing ovation.”

Sixteen-year-old Australian environmentalist Aelwen Johnstone talked about the program she leads called Millennium Kids. “Millennium Kids have a vision for our world. Our world, where all people have access to fresh water. Our world, where there is a safe place for all creatures big and small. Our world, where we care for the land and forests, the sea, rivers and wetlands. Our world, where we have clean air and less waste. Our world, where all schools learn about sustainability. Our world, where everyone works together for peace. We have a simple vision…let’s start today (because earth is the only planet with chocolate!)”

The group has hundreds of young members from Indonesia, Malaysia, South Africa and Europe as well as Australia. Johnstone recalled growing up “across from a cement plant, with no trees,” telling the audience, “I was just a little kid with a big idea. For seven years I’ve met with local, state and federal members of government. We’ve conducted workshops. Young people are uniquely qualified to offer fresh perspectives.” She said that the fact that her group is youth led makes it unusual. The intent is “to do project-based learning – we try to bring what we’ve learned outdoors into the classroom.” Theirs is “a mission we are passionately pursuing.” She added: “We are the architects of the future.”

Aelwen Johnstone:Photo Millennium Kids

Keith O’Herrin spoke about urban forestry as a profession: “I’m here to talk about us – urban foresters.”

For his dissertation thesis, O’Herrin investigated how people enter the field. Urban forestry provides ecosystem services; trees have to be managed by professionals. What defines an ideal profession? O’Herrin looked at doctors, lawyers, civil engineers – eleven fields in total. All of them, he said, relyupon credentialling, quality assurance of individuals, establishing a minimum level of skills and accountability. A comparable credential is something lacked in urban forestry. “Our profession is very young,” he told the crowd, “only around sixty years old. We’re not dysfunctional. Things are going to start happening quickly now.” He added, “We should have the optimism and joy that this conference gives us.”

Keith O’Herrin
Rebecca and Paul Johnson

Rebecca Johnson said, “There have been several talks that have been so inspiring. I’m going back home with new ideas – it’s rejuvenating!”


Dave Muffly presented on his experience planting nine thousand oak trees at Apple’s California headquarters.

“I had the opportunity of a million lifetimes to change the paradigm,” he said in his lecture, titled “Strange Paths to Paradigm Shift: How Steve Jobs Helped California Adapt to Climate Change,” Muffly enumerated some of the species he planted that he grew from acorns he collected in local native forests: California Valley oak, coast live oak, Gambel oak, Engelman oak and Island oak, “an ancient species that was widespread five hundred million years ago.”

Apple Oaks
Chris Donnelly, Ian Leahy

Chris Donnelly, Urban Forestry Coordinator at Connecticut DEEP, commented, “It’s been a very interesting group of people, especially with the international perspective. I’ve connected with an interesting set of ideas. It’s a lofty conference in that sense, but also very real.” According to Ian Leahy, Senior Advisor on Urban Forestry for American Forests: “I liked hearing Brenda Richardson from DC talking about connecting multigenerational trauma to trees. These events are an opportunity to have conversations you can’t have on Zoom to advance urban forestry.”

Cecil Konijnendijk spoke as a “global urban forester.” He told the audience about “a tree that grows in Manhattan, a Callery pear in the rubble of the World Trade Center after 9/11, nurtured and brought back to life. It’s a strong symbol of survival and community.” He also referenced Anne Frank, describing her as “a young girl in Amsterdam hiding from the Nazis, who sees a horse chestnut out her window and gets hope,” and described a Laotian family who derived a sense of meaning from a tiny garden.

“Trauma asks us to be resilient,” said Konijnendijk. “We need the power to bounce back. We’re living in a volatile world with climate stress and in which people are suffering but also surviving. Resilience means springing back. That neighborhood strength needs to be restored. There’s evidence that we can rebuild that resilience through contact with nature.” Trees, he said, “make us stronger, make us better.” We need to “re-entangle with our trees. We can build social cohesion. We can use tree equity by employing knowledge, empathy, and by being very professional. And professionalism is very apparent in this group. We need to be bold, we need to be radical. And we need to do what we do with love for what we do, why we do it, and with love for urban forestry.”

Cecil Konijnendijk

Kai Lintunen, head of International Communication at the Finnish Forest Association, entered the discussion in a slightly different way by focusing on wood as a building material. “Wood architecture is like a language,” Lintunen reminded the audience. Building with wood has all but disappeared. “And urban green areas cannot be virtualized.”

He said that building with wood and urban forestry is a natural combination. “Wood has resilience against adversity. Wood helps us bounce back. Wood withstands disasters with minimal damage.” He added, “The time is now for nature-based solutions. Innovation is on our side.” Building with sustainable wood stores carbon. Its low density makes it easy to reconfigure, and we need “to use less, use longer, use again, and make things better.” He ended on this note: “Rethink the solution. Rethink wood. Grow the solution.”

Wood Construction
Madelyn Bryant, Kenny Harmon, Ben Bukris

Madelyn Bryant, a student at Virginia Tech, said, “The keynote talks very optimistic. I appreciate that at a conference like this.” According to fellow Virginia tech student Kenny Harmon, “I like the informal conversations – when you talk to other foresters, they give you ideas about your own work.” Ben Buckris added, “I like being able to hear from people from all over the world. So often we think about the things we don’t do on a local scale, but with everyone being from all over the world you get so many perspectives on how people tackle the same issues in different ways.”

Gadwal Vijayalakshmi, the mayor of Hyderabad, India, shared the strides being made in her locale’s efforts to create green spaces with the management of 185 lakes, forests, 3,000 urban public parks and sixty “theme parks” such as a butterfly park and a maze garden.

Part of the effort has centered on planting medians and vertical gardens along highways. Fully 129 “urban lung spaces” are envisioned, with nearly 59 completed as of yet. Vijayalakshmi spoke about eco-friendly crematorium sites, and over 14,000 tree nurseries created in her province. “In the last decade,” she said, “forest cover has increased 147 percent.

Gadwal Vijayalakshmi
Rachel Habig-Myers

According to Urban Forester Rachel Habig-Myers, “The energy of the people in these spaces” is what matters the most. “It’s so beneficial. Learning in such a positive environment. The juice I get from these conversations lasts all year.”


Landscape architect Kate Chesebrough shared her experience in Nairobi, where grass and diverse trees have transformed a highway and inspired replication. “It’s a watershed moment for trees,” she said, noting a collaboration with Kenyan youth on a project that began in 2020 to plant native trees, proving the potential of rights of way to become biodiversity corridors. It is “a very female workforce,” Chesebrough said, “and women became expert in caring for trees because it was consistent, attractive and safe work that they were proud of.” The unofficial motto: “Grow slower, better.” The solution, she emphasized, is unique to Nairobi. “Otherwise it’s a graph. It’s a number.”

World Forum Audience:Photo Carolyn Cheatham Rhodes

Christine Carmichael spoke about sharing community engagement strategies across geographical borders. “We need to remember the racist roots of inequitable tree canopy due to the history of redlining in cities,” she said. One impact might be a tendency for there to be  “no-tree requests” in underserved communities, necessitating equitable engagement. She described the innovative project Root Nashville, “which recruits residents who are already trusted to find homes for fifty trees in their neighborhood, giving them one thousand dollars.” Past captains go on to help and mentor new cohorts.

Carmichael described the creation of “ward walks,” in which residents are asked to see what they like about the surroundings. What do they like about the canopy, and what would they like to see moving forward? Another project, Collecting Stories, utilizes a selfie contest in front of peoples’ favorite trees. It’s important, Carmichael stressed, to ask people about their personal experiences, and assessments need to be qualitative, not just quantitative. “We need to lean into networks that already exist,” she said, asking, “How can we share knowledge across international borders?”

25A-Selfie Contest
Anne Fege, Lydia Scott

Ann Fege said, “I started forestry school fifty years ago at Yale School of Forestry and Environmental Studies. And I’m still doing forestry.” Added Lydia Scott, “It’s the opportunity to hear new ideas around urban forestry – it regenerates your soul, I think.”

Some other key highlights from the World Forum:

Murphy Westwood, Vice President of Science and Conservation at Morton Arboretum, spoke about reducing “plant blindness” in a talk about how urban forestry can save threatened trees in the wild.

The words of Brenda Richardson resonated. The Coordinator for the Anacostia Parks & Community Collaborative spoke about “memory forests” that are “rooted in racial equity.” People might have “wounded ears,” she said, or “wounded eyes.” These “trauma breaks” might be personal or ancestral. A self-proclaimed “eco-feminist,” Richardson spoke from the heart.

The audience appreciated David Mashoulem’s admonition to “move at the speed of trust.” His program, “Speak for the Trees,” supported by the Environmental Protection Agency and focusing on three Boston EJ neighborhoods, teaches students to understand the relationship between science, nature and history. “They show up in force to learn about the trees in their communities,” he said. “We all have stories, and these powerful narratives need a trusted space to emerge.”

Brenda Richardson
Claire Sammons, Jake McDonald, Benjamin Ash

Claire Sammons said, “It’s great hearing ideas from different people, what they’re implementing. Atlanta has tree coverage, but also problems.” According to Jake McDonald: “I love the networking part – hearing about what other people do, their programs, and taking that home with you.” Benjamin Ash said he liked “learning about other takes, so I can apply it to my own city. What I like most of all is the macroscope perspective regarding forestry. I’ve only been in the field six or seven months, and I’m developing my city’s program. I’ve got to hear as much as possible.”


Won Sop Shin, Associate Professor at University of British Columbia, spoke about the Korean experience with “forest therapy,” saying that his country is “at the front line in terms of the hidden power of the forest.” He said that in Korea, “psychiatrists are using forests to treat depression and anxiety.”

Ecologist Cynnamon Dobbs spoke about “Types of Nature Users: Pathways Towards Our Health and Well-Being.” She told the gathering that “we’re good at saying trees are good for us. That’s a set of rules we already know. We’re good at knowing how to put trees into the ground. But are we providing benefits for all? What we need to focus on now is “distributional justice.”

Andrea Mechelli, Professor of Early Intervention in Mental Health at Kings College in London, made the point that “one issue in the field of mental health is that the main research comes from observation and not intervention studies, so we don’t know how best to translate nature for mental health. The evidence is already there – why is it that the translation to the real world is so limited? Nurses and doctors go through years of training. Why are these professionals not already learning about the benefits of nature? We have the science, but it has not been communicated. We need a holistic approach and some cognitive reframing to move forward.”

Ruby Olisemaka, Westchester Land Trust
Christina Smith
Rita Mintah, Ghana

Urban Health Specialist Jose Siri spoke about the “need to expand our idea of what evidence is. We need to build people into the research process.” On the subject of climate change: “You can’t understand it without first taking to heart the trend toward urbanization. The cities of tomorrow will be larger, more dense.” Global warming, he said, “will place resource burdens on governments, change priorities among all stakeholders. We need to think of it as an opportunity. Crisis creates opportunity.”

Michael Kelley described Pittsburgh’s tree equity initiatives. It’s important, he said, “to build a constellation of organizations that stay focused on equity. You need leadership and data about trees, but underneath you need a strong link to the community so they can drive the process.” He spoke about the city’s history of redlining, housing for the steel mills, no green spaces, economic collapse which led to a decrease of the population by fifty percent. “When development rebounded, it went to those groups with most proximity to power.” A tree inventory led to planting efforts, and a Tree Equity committee developed an “equity matrix,” which targeted areas of need. “People understand the benefits of trees,” he concluded, “but at the end of the day, these trees go in front of somebody’s home. They need to be able to trust trees to give them benefits.”

Urban Forester Colleen Berg stressed that, “We need to work to let people know they’re eligible for funding. The money is there. We should continue to build these bonds and not waste time making up scenarios that might not be the case. Equity work is experience based. It takes time.”

Kat Korba and Anni Bellows presented on the Urban Food Forest Project in Syracuse, a nine-mile food corridor of plantings in former vacant lots that Korba described as “going right through the heart of an EJ community.”

The initiative involved the restoration of a historic food trail through to Onondaga Lake, traditionally a long-house community, and was a collaboration between the city, the university, Onondaga Earth Corps and other local organizations. Bellows added that Syracuse has the highest poverty rates in the country, saying that eighty percent of all households with children qualify for free school lunches. The South Side, where the food forest is located, is an urban food desert. Plantings include pawpaw, which is native to twenty-six states and is a superfood that is nutritionally dense and disease resistant.

Kat Korba

Jessica Sanders, Executive Director of Sacramento Tree Foundation, talked about the critical importance of  “holistic stewardship,” or “thinking from seed to slab.”

“Trees create cities that are livable and lovable,” she said, describing projects that engage kids by harvesting acorns, asking them simply “Do you like to pick things up?” then growing them to seedlings. “The kids write them love letters,” she said. The city also partners with underserved communities so that anyone can get ten free trees delivered by the Sacramento Shade Program. She also talked about the importance of words. “Don’t talk about empowering communities!” she stressed. “They already have power!” There is also a program targeted to “removing trees when people don’t want you to. The Urban Wood Rescue Program makes this wood available. Every single piece of wood has a story. You can honor that rescued wood. It’s an entry point and a connection.”

Jessica Sanders
Laura Moser, Eric Bridges

Laura Moser said what she liked best about the conference was “putting faces and three-dimensional people to those squares on Zoom for the last three years. It’s the first time I’ve met some of my coworkers, collaborators and partners in person.”

London landscape architect Johanna Gibbons said, “We make the city. We’re making this habitat. We need to make it where we can not only survive but thrive. There are no trees without people in the city. We decide if we plant or maintain them.” London, she said, has eight million trees. “We shape the process. We’ve got that potential. And the forest shapes us.” Gibbons also said, “We talk about taking time, but we also don’t have much time in terms of climate change. So we need to come up with a prototype and then tweak it to prime the environment and the community for the process of change, so there is confidence that a tree is going to grow and so young people will be ambassadors into the future. We have to value what exists, and nurture the possible. We are the forest, and it’s in our hands.”

Cassandra Johnson Gaither, Research Social Scientist with the United States Forest Service, pointed out the common problems of “housing insecurity” and “involuntary neighborhood transience” in cities, which constrain poor peoples’ access to urban forests when people are forced to move from their homes. It’s especially problematic for African American women, as Black men are seven times more likely to be incarcerated, and there is a three times greater rate of eviction for Black women than white women. Corporations are buying up the housing stock and are more likely to evict tenants. “When neighborhoods are more volatile, people are less likely to be invested in greenspace. There is a lot of volatility in these communities. It’s important to understand these embedded problems.”

Social scientist Kathleen Wolf described her research among Peruvians living on the Amazon, building communities on rafts there. “I was so humbled by the people in those circumstances, how little they had and yet how generous they were. The idea of reciprocity is important when looking at Indigenous cultures. We get. How do we give back?”

Matt Spitsen, Program Manager of the Alliance for Community Trees, stressed that “there needs to be more nuance to community efforts. We need to find relevant metrics beyond planting trees. Participants who are offered jobs, say, after planting takes place.” He said, “Partner, partner, partner. Don’t think you have to reinvent the wheel. How can you work together?”

Urban Forester Eric Bridges summed up the view of perhaps most of the people at the 2nd World Forum, saying that what was most meaningful was, “Networking. The hallways are as good as the lecture rooms.”

Karla Nagy